Tokkai Sho 63-219956 published by the Japanese Patent Office in 1988 discloses an infinite speed ratio transmission device for vehicles using a toroidal continuously variable transmission (CVT).
In this transmission device, a CVT having a speed ratio which can be continuously varied, and a fixed speed ratio transmission, are connected in parallel to an input shaft joined to an engine, the rotation of the output shafts of the transmissions are input to a planetary gear set, and the final output rotation from the planetary gear set is extracted as a drive torque of the vehicle.
The rotation output of the CVT is input to a sun gear of the planetary gear set via a chain and a sprocket, and the output shaft of the fixed speed ratio transmission is joined to a planet carrier of the planetary gear set via a power circulation mode clutch.
A ring gear of the planetary gear mechanism is joined to a final output shaft.
The rotation output of the CVT is also input to the final output shaft via a direct connection mode clutch.
In a power circulation mode wherein a power circulation mode clutch is engaged and a direct mode clutch is disengaged, a speed ratio of the infinite speed ratio transmission device, i.e., the ratio of the rotation speeds of the input shaft and final output shaft, can be continuously varied from a negative value to a positive value including infinity according to the difference of the speed ratio of the CVT and the speed ratio of the fixed speed ratio transmission.
In a direct mode wherein the power circulation mode clutch is disengaged and the direct mode clutch is engaged, the product of the speed ratio of the CVT and a speed ratio due to chain transmission is the speed ratio of the infinite speed ratio continuously variable transmission.
Tokkai Hei 9-317837 published by the Japanese Patent Office in 1997 discloses a CVT having two sets of toroidal units and an intermediate wall which is provided between the toroidal units and support output disks via bearings. The intermediate wall comprises a pair of partitions which are fixed to brackets projecting inwards from a casing of the CVT by bolts.